How can I store recorded data from the NEST simulator in a binary format?

Question

I am trying to write spikedetector data into .gdf files in binary format, but I cannot.

I am setting the binary param of the spikedetector to True (I checked it using nest.GetStatus) but files are written in ASCII:

neurons = nest.Create('iaf_psc_alpha', 5)
sr = nest.Create('spike_recorder')
nest.Connect(neurons, sr)
sr.SetStatus({'binary': True})

I am using NEST 2.18

Answer 1

The documentation for NEST 2.18 and 2.20 is misleading in this respect. The binary option has no effect (it sets the ios::binary flag when opening the file, but that has no significant consequences).

If you want to write spikes in binary format, you need to switch to NEST 3.0 and use the sionlib recording backend by setting the recorder's record_to property:

neurons = nest.Create('iaf_psc_alpha', 5)
sr = nest.Create('spike_recorder')
nest.Connect(neurons, sr)
sr.SetStatus({'record_to': 'sionlib'})

A guide for recording from simulations is available in the docs.